House Republicans applauded President Donald Trump’s meeting with Kim Jong Un, but they displayed significantly less confidence than the president that North Korea’s denuclearization is now a foregone conclusion.

Upon returning to Washington on Wednesday morning following his historic summit with Kim in Singapore, President Trump fired off a series of tweets declaring the nuclear threat eliminated and assuring Americans they can “sleep well tonight.”

“Just landed - a long trip, but everybody can now feel much safer than the day I took office. There is no longer a Nuclear Threat from North Korea,” Trump tweeted.

The two leaders signed a brief joint statement Tuesday in which Trump promised unspecified security guarantees and Kim committed to “complete denuclearization of the Korean peninsula.” Secretary of State Mike Pompeo was directed to meet with North Korean officials as soon as possible to start hashing out details, but no specific steps toward those goals were defined.

After the summit, Trump told reporters he would halt “war games” the U.S. military regularly conducts with South Korean forces, deeming them provocative, expensive, and unnecessary. Many saw this as a significant concession to Pyongyang, but the administration stressed that the exercises can be easily resumed at any time.

“He made it very clear that the condition precedent for the exercises not to proceed was productive, good-faith negotiations being ongoing,” Pompeo told reporters in Seoul on Wednesday. “And at the point it’s concluded that they are not, the President’s commitment to not have those joint exercises take place will no longer be in effect.”

In assessing the post-summit status of the conflict over North Korea’s nuclear weapons, Republicans focused on the progress made rather than the uncertain path ahead.

“I give the president a lot of credit,” said Rep. Darin LaHood, R-Ill. “Six months ago, North Korea was firing ICBMs into the Pacific Ocean near Guam.”

Since then, Kim has returned three hostages to the U.S. and blown up a nuclear testing site as demonstrations of good will, and Trump agreed to the first face-to-face meeting between a North Korean leader and a sitting U.S. president.

“Presidents for 25 years in this country have tried to achieve what we achieved yesterday,” LaHood said, “so I’m anxious to hear the details and the follow-up, but I think we’ve made a lot of progress.”

Rep. Chuck Fleischmann, R-Tenn., said Trump deserves an A+ grade for securing “a tremendous opportunity and a historic win for the United States.”

He noted how far relations between the U.S. and North Korea have come since Trump and Kim were threatening and insulting each other in statements and tweets earlier this year.

“In a very short few months, actually a short few days, we’ve seen a complete turnaround,” he said.

Fleischmann echoed Trump’s assessment that Americans can rest easier with this agreement in place, though he also called for diligence and vigilance going forward in a process that will likely take years to complete.

“The people of East Tennessee, who for years have worked on nonproliferation issues, can feel safer,” he said.

According to Rep. Rodney Davis, R-Ill., the summit represented a clear victory for Trump and a refutation of the worst-case scenarios some critics had painted last winter.

“A lot of the president’s detractors thought America would be lobbing nuclear weapons at North Korea right now,” Davis said, “and here we are. He was shaking hands.”

Rep. Brian Babin, R-Texas, also brushed off some of the complaints leveled against the president over the summit.

“I’m hearing a lot of Democrats and even some Republicans criticizing this thing,” he said. “What is the objective here? The objective is to denuclearize and to try to prevent an unthinkable nuclear conflict. Who would have ever thought five or six months ago that our president would be sitting down with Kim Jong Un of North Korea, and here we have it.”

However, Babin acknowledged many details still need to be worked out, including parameters for thorough inspections to confirm North Korea truly is disarming.

“The exact same thing that needs to be done in Iran and was not being done properly,” he said, referring to the inspections regime implemented by the Iran nuclear deal that Trump has called insufficient. “I think the president was absolutely correct when he pulled us out of the Iranian deal. He’s not going to sign any deal where we can’t properly verify what’s going on.”

Democrats and some North Korea experts saw the president’s triumphant tweets as a premature celebration based on a very broad statement of agreement with Kim that prescribed no concrete course of action.

“You know what the ‘no longer a nuclear threat from North Korea’ statement by @realDonaldTrump reminds me of?,” tweeted Rep. Ted Lieu, D-Calif. “The big banner behind President Bush during his Iraq speech that said: MISSION ACCOMPLISHED P.S. We are still in Iraq.”

Rep. Dan Kildee, D-Mich., welcomed the president’s commitment to diplomacy, but he expressed concern that Trump gave up too much and got too little in return. In particular, he worried ending joint military exercises would hamper the U.S. and South Korea’s ability to respond to an attack on Seoul using conventional weapons.

“We have to make sure we’re prepared and I was disappointed the president was so able in a cavalier fashion to dismiss those exercises,” he said.

Kildee emphasized that he believes engaging with Kim is the right path, but he also warned against putting much faith in Kim’s word.

“The president needs a dose of realism,” he said. “I think he was so focused and so anxious on having a photo op where he got to sign any piece of paper to make it look as though he’s acting in a positive and diplomatic fashion that he was willing to give away what I think was an important concession.”

Rep. Suzanne Bonamici, D-Ore., agreed Trump’s diplomatic approach is promising and far preferable to Twitter feuds over the size of the leaders’ nuclear buttons, but she fears the statement agreed upon by Trump and Kim was too vague to be meaningful.

“I’m concerned the approach of the president was analogous to trying to get a good hotel built on the beach, rather than an agreement dealing with nuclear weapons,” she said. “That involves preparation, expertise, and thoughtful discussions about commitments and policies.”

Bonamici was also troubled by President Trump’s effusive praise for Kim, whom he called a smart, talented negotiator who is loved by his people.

“It’s appalling that the president is praising a brutal dictator while alienating our allies like Canada,” she said, referring to Trump’s recent attacks on Canadian Prime Minister Justin Trudeau. “That just doesn’t make sense to me.”

Even some Republicans are urging caution in light of North Korea’s many previous commitments to denuclearize, none of which the regime has abided by. It also remains unclear whether past disputes about timing and terms that have derailed negotiations before have been resolved.

“I’m hesitant that their regime is going to do anything different than they have in the past,” Davis said.

Complications and questions have already arisen. South Korean officials indicated Tuesday they were unaware of Trump’s commitment to end “war games” until he announced it to the press and Vice President Mike Pence told Senate Republicans some military exercises and training would continue.

Both sides have made unverified assertions about the other’s position in the wake of the summit. Trump told reporters Kim made additional commitments that were not included in the written statement due to lack of time, but North Korean state media is now claiming Trump made significant concessions he has not publicly confirmed.

According to the Korean Central News Agency, Trump and Kim agreed to “abide by the principle of step-by-step and simultaneous action” and to the lifting of economic sanctions. Trump said publicly sanctions would not be lifted until “the nukes are no longer a factor,” and he and Secretary Pompeo have often derided the path of incremental denuclearization.

Pompeo told reporters Wednesday the administration’s expectations for complete and verifiable denuclearization have been clearly communicated to Kim. He declined to specifically address what North Korean media is reporting, saying, “I’m going to leave the content of our discussions as between the two parties, but one should heavily discount some things that are written in other places.”

Despite Pompeo’s assurances, Democrats remain skeptical.

“We can’t trust Kim,” Kildee said. “We can’t trust North Korea on their word that they won’t again engage in belligerent behavior.”